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Hot Water Heaters

I want to replace my old gas hot water heater with a energy effocent system ,The one with no holding tank ,instant hot water this apppeals to me because now there is onl my wife and I living in the house 20,000 sq ft.(app)with two full baths and a 1/2bath in the laundry room in the basement(play room ajacant)I live in New England in a suburb about 20 miles out side Boston away frim the Oacean in the town of Bedford.I would appreciate you comparing the different Moddels and Manufactures so I may be able to make a better decison on my purchase.

Re: Hot Water Heaters

Only one caution comes to mind. You do not want to use a tankless water heater in situation where the water ultimately heats your home. Granted this quote is taken from a retailer trying to sell you their product but it holds true even so. "What about 'instant' or 'on-demand' water heaters as a heat source?" "They work well when they are used to heat only domestic hot water, where opening a tap creates the pressure differential to open the gas valve and modulate the flame. In closed radiant heating systems, this pressure differential must be created through the addition of powerful pumps, an expensive solution. In addition, many on demand water heaters require metal or masonry chimneys, an indicator of marginal operating efficiency. If you have electric heat or solar heat it may be economical to use a tankless water heater. One side note: look at the energy efficiency of your tankless water heater. If I am right it is in the 65% to 70% range meaning 30 to 35% of the heat it produces is going straight up the chimney. Compare that to a Polaris tanked model which has a 94 to 96% efficiency.

Two other possibilities you may want to consider. Install solar hot water for your heat and use the tankless for your hot water. Option 2: separate your hot water needs, use the tankless for your potable hot water and a tanked model for the heat. Option 2 if you did an electric water heater for the heat you could install a heavy duty switch where easily accessible and only turn it on when you want heat, thereby meaning that it won't use electricity to heat the water if you don't need it. One caution to option 2, if you can throw on a sweater and be good for an hour or 2 while the heater builds up heat it may be good. If not then you should steer clear of option 2. Also have the pumps that feed the heat connected to that switch also so that they only pump when there is hot water to pump. otherwise they will continually pump cold water or burn out.

Re: Hot Water Heaters

Originally Posted by rleary301

I want to replace my old gas hot water heater with a energy effocent system ,The one with no holding tank ,instant hot water this apppeals to me because now there is onl my wife and I living in the house 20,000 sq ft.(app)with two full baths and a 1/2bath in the laundry room in the basement(play room ajacant)I live in New England in a suburb about 20 miles out side Boston away frim the Oacean in the town of Bedford.I would appreciate you comparing the different Moddels and Manufactures so I may be able to make a better decison on my purchase.

Thank you Richard Leary

Common misconception --- they are not " instant " water heaters but rather "On Demand " --- they won't supply hot water any quicker than a conventional water heater..

Re: Hot Water Heaters

Canuk is right tankless water heaters are not instant water heaters. There are instant water heaters aka point of use water heaters (usually electric) that are placed under say the kitchen sink. I do not believe this type is enough to take care of a shower or laundry room.
I have a Rinnai tankless water heater that I have had for the past 3 years and I love it. Not sure what type Eric is talking about but mine is about 94% efficient and vents through PVC pipe not through a chimney. They are not cheap but if you plan to stay in the house they will pay for themselves in a fairly short amount of time depending on water usage. Another benefit or at least potential benefit is a tankless water heater is expected to last 25 years or more. In 25 years you will put in at least 2 to 3 regular tank style water heaters. Hope this info helps you out.